[PATCH] drm: Support drivers with threaded irqs

[Thomas Hellstrom]

On 08/09/2017 07:40 PM, Daniel Vetter wrote:
> On Wed, Aug 09, 2017 at 07:38:29PM +0200, Daniel Vetter wrote:
>> On Wed, Aug 09, 2017 at 07:17:54PM +0200, Sinclair Yeh wrote:
>>> From: Thomas Hellstrom <thellstrom at vmware.com>
>>>
>>> See LWN article at
>>> https://urldefense.proofpoint.com/v2/url?u=https-3A__lwn.net_Articles_302043_&d=DwIBAg&c=uilaK90D4TOVoH58JNXRgQ&r=wnSlgOCqfpNS4d02vP68_E9q2BNMCwfD2OZ_6dCFVQQ&m=NYyVOtVu5iQrNCGt-QcVtR_IU0lhhztOmFP3qnN88tc&s=ruWozYT16Yk3p7sIscOFDNKCC1_WHX_7ChY7q5Ko4vw&e=
>>>
>>> Signed-off-by: Thomas Hellstrom <thellstrom at vmware.com>
>>> Reviewed-by: Deepak Singh Rawat <drawat at vmware.com>
>>> Reviewed-by: Sinclair Yeh <syeh at vmware.com>
>> We definitely can't do this in general due to latency reasons.  Please
>> read the kerneldoc of drm_irq_install and just roll your own. This also
>> seems to like break every driver's compilation.
> Oops misread, I thought you rename stuff instead of adding. I still don't
> see the point - drm_irq_install happened because of the *bsd abstraction
> layer, not because it's actually all that useful.
> -Daniel

So the whole point of this is to replace the vmwgfx tasklets with 
treaded irqs to be nicer on the system. Seems like no other drivers use 
tasklets at this point.

The vmwgfx driver is using drm_irq_install(), Of course we could 
duplicate that code into the driver, but I don't see the point in doing 
that nor how this would violate what's written in the drm_irq_install 
kerneldoc? It just extends its functionality somewhat.

Thomas